I've read quite a few comments of people complaining about grainy view with the Oculus Rift as well, although I didn't tried it first hand. That's what happened when you put a small screen so close to your face.
You can check out this post on oculus.com. The guy said, and I quote: "I do see pixellation but am not sure what the big deal is.". I think that if you do focus on the bad you'll definitely going to find it. So pixelation is there, but it's not an issue. most people who tried the Rift and Vive really enjoy it, and I didn't hear anyone complaining about pixelation so much. I assumed that it's going to be worse on the PSVR display, but read this article, the display technology is very important, so I think that we can expect good visuals even though the resolution is slightly lower.